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std::is_volatile(3)	       C++ Standard Libary	     std::is_volatile(3)

NAME
     std::is_volatile - std::is_volatile

Synopsis
	Defined in header <type_traits>
	template< class T >		 (since C++11)
	struct is_volatile;

	std::is_volatile is a UnaryTypeTrait.

	If  T  is  a  volatile-qualified  type	(that  is,  volatile,  or  const
     volatile), provides
	the member constant value equal to true. For any other	type,  value  is
     false.

	If   the   program   adds   specializations   for   std::is_volatile  or
     std::is_volatile_v, the
	behavior is undefined.

Template parameters
	T - a type to check

	Helper variable template

	template<  class  T  >						  (since
     C++17)
	inline constexpr bool is_volatile_v = is_volatile<T>::value;

     Inherited from std::integral_constant

Member constants
	value	 true if T is a volatile-qualified type, false otherwise
	[static] (public static member constant)

Member functions
	operator bool converts the object to bool, returns value
		      (public member function)
	operator()    returns value
	(C++14)       (public member function)

Member types
	Type	   Definition
	value_type bool
	type	   std::integral_constant<bool, value>

Possible implementation
	template<class T> struct is_volatile : std::false_type {};
	template<class T> struct is_volatile<volatile T> : std::true_type {};

Example
     // Run this code

      #include <type_traits>
      #include <valarray>

      static_assert(!std::is_volatile_v<int>);
      static_assert(std::is_volatile_v<volatile int>);
      static_assert(std::is_volatile_v<volatile const int>);
      static_assert(std::is_volatile_v<volatile std::valarray<float>>);
      static_assert(!std::is_volatile_v<std::valarray<volatile float>>);

      int main() {}

See also
	is_const checks if a type is const-qualified
	(C++11)  (class template)

http://cppreference.com 	   2024.06.10		     std::is_volatile(3)
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